title: Serine utilization by Klebsiella aerogenes.
abstract: Klebsiella aerogenes was found to contain a specific L-serine dehydrase that was induced by threonine, glycine or leucine, but not by its substrate. Cellular concentrations were sensitive to carbon rather than nitrogen sources in the growth medium. A nonspecific isoleucine-sensitive L-threonine dehydrase supplemented the specific L-serine dehydrase activity. K. aerogenes also contains a leucine-inducible L-threonine dehydrogenase which probably initiated a threonine-utilization pathway in which the serine-specific dehydrate participated. Strains that were altered in their ability to metabolize serine differed in either L-serine dehydrase or L-threonine dehydrase activity. Thus, K. aerogenes growing on L-serine as a sole nitrogen source relies upon two enzymes that metabolize the amino acid as subsidiary functions.
mesh_terms: D004790:Enzyme Induction; D004794:Enzyme Repression; D006863:Hydrogen-Ion Concentration; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000378:metabolism*; D012695:L-Serine Dehydratase / Q000378:metabolism*; D009154:Mutation; D012694:Serine / Q000378:metabolism*; D013913:Threonine Dehydratase / Q000378:metabolism*
chemical_list: D012694:Serine; D012695:L-Serine Dehydratase; D013913:Threonine Dehydratase